group php array by subarray value - php

Question

I want to group an array by a subarray's value. If I have an array like this:
Array
(
[0] => Array
(
[userID] => 591407753
[propertyA] => 'text1'
[propertyB] => 205
)
[1] => Array
(
[userID] => 989201004
[propertyA] =>'text2'
[propertyB] => 1407
)
[2] => Array
(
[userID] => 989201004
[propertyA] => 'text3'
[propertyB] => 1407
)
)
I want to sort to group this array by a subarray's value so I can have an array like this:
Array
(
[0]=>Array
(
[userID]=>59140775
[properties]=>Array
(
[0]=>text1
)
[propertyB]=>205
)
[1]=>Array
(
[userID]=>989201004
[properties]=>Array
(
[0]=>'text2'
[1]=>'text3'
)
[propertyB]=>1047
)
)
How can I make this?
Before I had tried this:
$result = array();
foreach ($userArray as $record)
{
$id=$record['userID'];
if(isset($result[$id]))
{
$result[$id]['propertyA'][]=array($record['propertyA']);
}
else {
$record["propertyA"]=array($record['propertyA']);
unset($record['tweet']);
$result[$id]=$record;
}
}
the problem was for the propertyA. I was an the result an additional property propertyA with the table like this:
Array
(
[0]=>Array (
[userID]=>989201004
[propertyA]=>'text2'
[properties]=>Array(
[0]=>'text2'
[1]=>'text3'
)
)
)

Answer 1

The following code should do the job. I hope it is self-explanatory:
$result = array();
foreach ($array as $record) {
if (!isset($result[$record['userID']])) {
$result[$record['userID']] = array(
'userID' => $record['userID'],
'properties' => array($record['propertyA']),
'propertyB' => $record['propertyB'],
);
}
else {
$result[$record['userID']]['properties'][] = $record['propertyA'];
}
}
$result = array_values($result);